The objective of this Phase II project is to provide an affordable and unobtrusive portable oxygen supply for COPD patients. Long term oxygen therapy (LTOT)-continuous oxygen combined with exercise-dramatically increases survival rates for these patients. Development of a safe battery operated device that does not interfere with normal daily activities will promote patient compliance with therapy and enhance their quality of life. This research project supports the NHLBI's mission to direct research in the development of devices related to the treatment and rehabilitation of patients suffering from lung disease. The portable oxygen concentrator under development will weigh less than 1.5 kg, yet will deliver the required 2-3 liters per minute (Lpm) equivalent oxygen flow for a period of 6 hours. This dramatic performance improvement over existing portable concentrators will be achieved by re-engineering the concentrator architecture. Three dimensional prototyping will be used to create energy storage, power transmission, and inertial damping components that share functionalities and thus reduce device mass. Fast kinetics air separation adsorbents being developed as SDGroup and elsewhere will enable the application of a proprietary rapid cycle, energy recuperative design that reduces power consumption to 15W/Lpm delivered oxygen. Adaptive power control algorithms will be developed to coordinate sensor input, patient data, and conserver functions. A patient data log will be integrated into the device, allowing the respiratory clinician to confirm compliance and personalize therapy. Chronic Obstructive Pulmonary Disease (COPD) afflicts over 12.5 million people in US and is the fourth leading cause of death. Exercise combined with continuous oxygen therapy has been shown to be the most effective treatment for this disease. This project will develop an extremely compact, lightweight and quiet portable oxygen concentrator that will augment patient compliance and improve quality of life for hypoxemic COPD patients requiring long term oxygen therapy (LTOT). [unreadable] [unreadable] [unreadable]